@Terry60:
Thank you. That both explains and solves the problem.
I followed your suggestion : I deleted the Linux entry from the BCD using "Edit Boot Menu", deleted all the ANG files from c:\, and added the Linux entry again. That created ANG0, and I can successfully boot into both Linux and Windoze.
The reason I had so many ANG files is:
1) I frequently have to rebuild the BCD after a Linux kernel update (which presumably changes the location of the Linux boot record), because otherwise I have boot problems.
2) Apparently "Reset BCD" does NOT delete the related ANG file(s), although deleting the entry from using "Edit Boot Menu" does.
3) So, every time I reset the BCD and added the Windoze and Linux entries again, it created a new ANG file without deleting the old.
This suggests that instead of "Reset BCD", I should have just deleted and re-added the Linux entry, which is what I will do in the future.